JP3964899B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus used for reading an image of a document by being incorporated in a facsimile apparatus or various scanner apparatuses.

  As is well known, this type of image reading apparatus is generally configured by assembling predetermined necessary parts to a synthetic resin case (see, for example, Patent Document 1). 6 and 7 show an example of such a conventional image reading apparatus. The illustrated image reading apparatus B includes a case 101 in which a transparent cover 102 is mounted on an upper surface portion, and a band plate-like substrate 103 assembled to the bottom portion of the case 101. The case 101 is assembled with a light guide 105 held by a reflector 106 and a lens array 107. The substrate 103 is provided with a light source 104 and a sensor IC chip 108 arranged in a line in the longitudinal direction of the substrate 103. The light emitted from the light source 104 passes through the light guide 105 and then irradiates and reflects the original P via the transparent cover 102, and the reflected light passes through the lens array 107 and passes through a plurality of sensor IC chips 108. It is configured to focus on a plurality of light receiving elements (not shown) built in. Each light receiving element outputs an image signal of an output level corresponding to the amount of light received, and a read image is obtained by performing processing based on these signals.

  In this image reading apparatus B, a peripheral wall portion 101a that protrudes downward is formed at the periphery of the bottom portion of the case 101, and the substrate 103 is assembled to the case 101 by being fitted into a recess 101b inside the peripheral wall portion 101a. It has been. The peripheral wall portion 101 a has a function of preventing light and foreign matters outside the case 101 from entering the case 101 through between the case 101 and the substrate 103. A connector 109 is provided at one end in the longitudinal direction of the substrate 103. The connector 109 is for connecting the substrate 103 to a desired external device, and is provided so that a part thereof protrudes from one longitudinal edge portion of the substrate 103. For this reason, the notch part 101c is formed in the part corresponding to the connector 109 of the surrounding wall part 101a, and interference with the connector 109 and the surrounding wall part 101a at the time of attaching the board | substrate 103 to the case 101 is avoided.

  Here, the notch 101c is generally connected to the connector 109 for the purpose of surely avoiding interference with the connector 109, or for providing versatility to a plurality of types of connectors having different sizes. It is formed in a size larger than the interference part. Then, in a state where the substrate 103 is assembled to the case 101, a relatively large gap c1 is generated between the notch 101c and the connector 109, and light and foreign matter are allowed to enter from the outside of the case 101 through the gap c1. The For this reason, as shown in FIG. 7, the case 101 is integrally formed with a partition wall portion 101 d that protrudes downward at a position closer to the light receiving element than the notch portion 101 c and corresponding to the notch portion 101 c. Thus, light and foreign matter are prevented from entering the light receiving element side in the case 101.

  However, in the image reading apparatus B according to the above-described prior art, the intrusion prevention of foreign matters has not been sufficient. Specifically, when the substrate 103 is assembled to the case 101, a minute gap may be generated between the front end of the partition wall 101d and the surface of the substrate 103 due to the tolerance of the dimensions of each component. Further, the gap c <b> 2 may be positively provided for the purpose of avoiding interference between the partition wall 101 d and the mounted component on the substrate 103. Then, foreign matter may enter the light receiving element side in the case 101 through the gap c2 and adhere to the light receiving element. In this case, the light cannot be properly sensed by the light receiving element, and the quality of the read image is increased. There was a problem such as worsening.

  On the other hand, the image signal is easily affected by electrical noise, and this noise may be mixed in the image signal, resulting in poor read image quality. For this reason, an electrode as a noise shield may be formed in the case 101. FIG. 8 shows an example of such a case. The electrodes 110A and 110B are formed by applying, for example, silver paste having excellent conductivity on the substrate 103 and the lower end surface of the partition wall 101d of the case 101. . The electrode 110A is connected to wiring (not shown) provided on the substrate 103, and the electrode 110B is grounded via a solder bump 111 formed on the electrode 110A. As a result, the case 101 is not excessively charged, and noise is prevented from being mixed into the image signal.

  However, according to the configuration in which the electrodes 110A and 110B are provided as described above, silver particles contained in the electrodes 110A and 110B may be scattered. If the scattered silver particles adhere to the light receiving element, the light cannot be properly detected by the light receiving element, and the quality of the read image is deteriorated.

JP 2004-193773 A

  The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide an image reading apparatus capable of avoiding adhesion of foreign matters on a light receiving element and obtaining an appropriate read image. It is said.

  In order to solve the above problems, the present invention takes the following technical means.

The image reading apparatus provided by the present invention includes a case, a band plate-like substrate assembled to the case, and can be accommodated in the case, and arranged in a row in the longitudinal direction of the substrate. a plurality of light receiving elements of the image reading provided on the substrate, each formed by coating a conductive paste on the case and the board, and includes an electrode in which at least some of them are opposed to each other, the The image reading apparatus is characterized in that a weir member protruding in the thickness direction of the substrate is provided between the plurality of light receiving elements on the substrate and the electrode.

  According to such a structure, it is avoided appropriately that a foreign material adheres to a light receiving element. That is, a weir member that protrudes in the thickness direction of the substrate is provided at an appropriate position between the plurality of light receiving elements and the electrode, so even if the component particles of the electrode are scattered, the component particles are separated from the electrode side by the weir member. It is appropriately avoided that the component particles of the electrode adhere to the light receiving element provided on the substrate. Therefore, according to the present invention, an appropriate read image can be obtained.

  In a preferred embodiment of the present invention, the board is provided with a connector for connecting the board to an external device, and the case is provided with a notch for avoiding interference with the connector. The dam member is provided between the plurality of light receiving elements and the notch.

  According to such a configuration, a gap is generated between the notch portion and the connector, and the dam member is provided between the plurality of light receiving elements and the notch portion even when foreign matter enters the case through the gap. Since it is provided at an appropriate place, the foreign matter that has entered the case is blocked by the weir member on the cutout side. Therefore, it is possible to appropriately avoid foreign matters from adhering to the light receiving element, and an appropriate read image can be obtained.

  In a preferred embodiment of the present invention, the dam member has a belt-like portion extending in substantially the same direction as the direction in which the plurality of light receiving elements are arranged.

  According to such a configuration, it is possible to efficiently block foreign substances and component particles of the electrode, and the width of the belt-shaped portion can be made narrow. Therefore, it is possible to appropriately avoid the attachment of foreign matter and component particles of the electrode on the light receiving element while reducing the area where the dam member is provided.

  In a preferred embodiment of the present invention, the dam member is made of synthetic resin. Furthermore, in the present invention, the dam member is preferably made of a silicone resin.

  According to such a configuration, even if the weir member is provided on the substrate, the conductive portion on the substrate is not unduly conducted, and the operation of the image reading apparatus is not adversely affected. If the weir member is made of silicone resin, the weir member itself has adhesiveness. As a result, the foreign matter adhering to the weir member does not scatter again, which is suitable for avoiding the foreign matter from adhering to the light receiving element.

  Other features and advantages of the present invention will become more apparent from the following description of the embodiments of the invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 4 show an example of an image reading apparatus according to the present invention. The image reading apparatus A according to the present embodiment is used as, for example, a component of a scanner that is fed by a platen roller R, and includes a case 1, a transparent cover 2, a substrate 3, a light source 4, a light guide 5, and a reflector 6. , A lens array 7, a plurality of sensor IC chips 8, a connector 9, electrodes 10 </ b> A and 10 </ b> B, and a weir member 20.

  The case 1 is made of, for example, a synthetic resin containing carbon fiber and has a box shape extending in the main scanning direction. The transparent cover 2 is, for example, an elongated rectangular glass plate or synthetic resin plate in plan view, and is attached to the upper surface portion of the case 1 so as to close the upper surface opening of the case 1. The lens array 7 is configured by holding a plurality of lenses 71 arranged in a row on an elongated block-shaped synthetic resin holder 70 extending in the main scanning direction. As each lens 71, for example, a rod lens is used. It is used. The lens array 7 is assembled to the case 1 so as to face the back surface of the transparent cover 2.

  The light source 4 is, for example, a resin package of three types of LED chips that emit light of each color of R, G, and B, and is mounted on the surface of one end portion in the longitudinal direction of the substrate 3.

  The light guide 5 is for efficiently guiding the light emitted from the light source 4 to the entire area of the document reading area S of the transparent cover 2, and has a block shape extending in the longitudinal direction of the case 1. The light guide 5 is made of, for example, an acrylic transparent resin such as PMMA, or other members having excellent light transmittance, and the surfaces of the various parts are all mirror surfaces. A plurality of recesses (not shown) are provided on the lower surface of the light guide 5 at predetermined intervals in the longitudinal direction. When light traveling in the light guide 5 is incident on each of the recesses, the light is scattered and reflected in various directions, and can be emitted toward the image reading region S from the light emitting surface 5a.

  The reflector 6 is composed of a first member 61 and a second member 62 having a total length corresponding to the total length of the light guide 5, and the light guide 5 is sandwiched between them to sandwich the light guide 5. It comes to hold. The first and second members 61 and 62 are made of, for example, a white resin and have high light reflectivity in order to prevent light emitted from the light source 4 from leaking to the outside of the light guide 5. It is said that. Reflective surfaces 61a and 62a into which the light guide 5 can be inserted are formed on the first and second members 61 and 62, and the light emitted from the light source 4 is totally reflected on each surface of the light guide 5. The reflection or reflection on the reflection surfaces 61a and 62a proceeds repeatedly, and is irradiated from the light irradiation surface 5a of the light guide 5 toward the document reading region S. The reflector 6 is assembled to the case 1 with the light guide 5 held integrally.

  The plurality of sensor IC chips 8 is a semiconductor chip in which an integrated circuit including a plurality of light receiving elements 80 is built, and is connected to the main scanning direction (longitudinal direction of the substrate 3) so as to be arranged in a row. Mounted on the surface. The plurality of sensor IC chips 8 are configured such that the light passing through the lens array 7 can be received by the respective light receiving elements 80 when the substrate 3 is attached to the bottom of the case 1. Each light receiving element 80 has a photoelectric conversion function, and is configured to output a signal (image signal) of a level corresponding to the amount of received light when receiving light on a predetermined light receiving surface.

  The substrate 3 is, for example, a ceramic band plate, and a connector 9 for connecting the substrate 3 to a desired external device is provided at one end in the longitudinal direction. On the surface of the substrate 3, wiring (not shown) for electrically connecting the connector 9, the light source 4, and the plurality of sensor IC chips 8 is provided. Power supply to the light source 4 and input / output of various signals to the plurality of sensor IC chips 8 are performed via the wiring and the connector 9.

  The substrate 3 is assembled to the bottom of the case 1 so as to close the bottom opening of the case 1. More specifically, a peripheral wall portion 1a that protrudes downward is formed on the periphery of the bottom portion of the case 1, and the substrate 3 is assembled to the case 1 by being fitted into the concave portion 1b inside the peripheral wall portion 1a. ing. The peripheral wall 1 a prevents foreign matter such as light outside the case 1 and dust / dust from entering the case 1 between the case 1 and the substrate 3. A notch 1c is formed in a portion corresponding to the connector 9 of the peripheral wall 1a, and interference between the connector 9 and the peripheral wall 1a when the substrate 3 is assembled to the case 1 is avoided. The cutout portion 1 c is formed in a size larger than the portion that interferes with the connector 9. Therefore, in a state where the substrate 3 is assembled to the case 1, a relatively large gap c <b> 1 is generated between the notch 1 c and the connector 9. The case 1 is integrally formed with a partition wall portion 1d that protrudes downward from a position corresponding to the notch portion 1c and closer to the light receiving element 80 with respect to the notch portion 1c.

  As shown well in FIGS. 3 and 4, the electrodes 10A and 10A are formed on the wiring of the substrate 3 and on the lower end surface of the partition wall 1d of the case 1 (the region indicated by broken line cross-hatching in FIG. 4). 10B is formed so that at least a part of these faces each other. The electrodes 10 </ b> A and 10 </ b> B are formed, for example, by applying a silver paste, and are located in the vicinity of the connector 9. The silver paste is obtained by mixing silver particles into a resin binder and further mixing with a viscous medium composed of an organic resin and a solvent to form a paste. Solder bumps 11 are formed on the electrode 10A facing the electrode 10B. The electrode 10A is connected to the wiring, and the electrode 10B is grounded via the solder bump 11 and the electrode 10A. As a result, the case 1 is not excessively charged, and noise is prevented from being mixed into the image signal.

  3 and 4, a weir member 20 that protrudes in the thickness direction of the substrate 3 is provided on the surface of the substrate 3 via an adhesive or the like. The weir member 20 is made of, for example, a silicone resin, and includes a first belt-like portion 20A extending in the main scanning direction (longitudinal direction of the substrate 3), and a second belt-like portion 20B extending in the sub-scanning direction (short direction of the substrate 3). Are integrally formed. The dam member 20 is provided so as to correspond to the positions of the notch 1c and the electrodes 10A and 10B. Taking an example of the dimensions of the substrate 3 and its periphery in the present embodiment, the length of the substrate 3 in the longitudinal direction is about 230 mm, the width W3 of the substrate 3 is about 14 mm, and from the surface of the substrate 3 to the inner peripheral bottom surface of the case 1 The distance H2 is about 1.2 mm, and the distance d from the notch portion 1c to the first belt-like portion 20A is about 7 mm. The dimensions of each part of the weir member 20 when the above dimensions are defined are such that the height H1 of the weir member 20 is about 0.55 to 1.1 mm, and the width W1 of the first and second belt-like parts 20A and 20B. , W2 is about 1 to 1.5 mm, the length L1 of the first belt-like portion 20A is about 20 to 22 mm, and the length L2 of the second belt-like portion 20B is about 4 to 5 mm.

  Next, the operation of the image reading apparatus A will be described.

  First, when the light source 4 emits light, the light is guided to the light guide 5, and travels repeatedly by being totally reflected on each surface of the light guide 5 or reflected on the reflecting surfaces 61 a and 62 a of the reflector 6. The light is irradiated from the light irradiation surface 5a of the light body 5 toward the document reading area S. Then, the light reflected by the surface of the document P on the image reading area S passes through each lens 71 of the lens array 7 and is received by each light receiving element 80 built in the sensor IC chip 8. As a result, an image of the original P is formed on the plurality of light receiving elements 80, and the image signal output from each light receiving element 80 is processed to obtain a read image.

  In the electrodes 10A and 10B, the adhesion may be reduced due to volatilization of the solvent contained in the silver paste that is the material, and silver particles may be scattered from the surfaces of the electrodes 10A and 10B. The weir member 20 is provided between the plurality of light receiving elements 80 and the electrodes 10A and 10B so as to correspond to the positions of the electrodes 10A and 10B. As a result, damming is performed on the electrodes 10A and 10B side. Therefore, adhesion of the silver particles on the light receiving element 80 is appropriately avoided, and an appropriate read image can be obtained.

  Even when foreign matter enters from the outside of the case 1 through the gap c1 and further enters the case 1 through the gap c2 below the partition wall 1d, the dam member 20 is connected to the plurality of light receiving elements 80. Since it is provided so as to correspond to the position of the notch portion 1c between the notch portion 1c, the foreign matter that has entered the case 1 is dammed to the notch portion 1c side by the dam member 20. Accordingly, it is possible to appropriately prevent foreign matter from adhering to the light receiving element 80.

  In the present embodiment, the dam member 20 has a first belt-like portion 20A extending in the main scanning direction. In other words, the first strip portion 20A extends in substantially the same direction as the direction in which the plurality of light receiving elements 80 are arranged. Since silver particles and foreign substances are considered to diffuse uniformly from the electrodes 10A, 10B, the gap c1, and the like to the periphery thereof, the first strip 20A is formed along the direction in which the plurality of light receiving elements 80 are arranged. Silver particles and foreign substances can be efficiently blocked, and the width w1 of the first belt-like portion 20A can be made narrow. Therefore, it is possible to appropriately avoid the adhesion of silver particles or foreign matters on the light receiving element 80 while reducing the area where the dam member 20 is provided. Further, it is preferable to form the first band-shaped portion 20A with a narrow width because it is easy to avoid interference with other components such as capacitors and jumpers (not shown) provided as appropriate on the substrate 3. In the present embodiment, since the electrodes 10A and 10B and the connector 9 are formed at one end of the substrate 3, the second belt-like portion 20B is integrated with the first belt-like portion so as to be substantially orthogonal. By providing, invasion of silver particles and foreign matters to the one end side of the substrate 3 from the second band-like portion 20B is appropriately prevented.

  In this embodiment, the dam member 20 is made of silicone resin. By configuring the weir member 20 with an insulator such as a silicone resin, the conductive portion on the substrate 3 is not unduly conducted, and the operation of the image reading apparatus A is not adversely affected. In addition, since the silicone resin has adhesiveness, the foreign matter adhering to the dam member 20 is not scattered again, which is suitable for avoiding the foreign matter from adhering to the light receiving element. Of course, the weir member in the present invention is not limited to the one made of silicone resin, and may be composed of another synthetic resin having electrical insulation.

  The image reading apparatus provided by the present invention is not limited to the above embodiment.

  In the above embodiment, the weir member 20 is configured by the first belt-shaped portion 20A and the second belt-shaped portion 20B, but the present invention is not limited to this. For example, as shown in FIG. 5, the dam member 20 may be composed of only the belt-like portion 20 </ b> C along the direction in which the plurality of light receiving elements 80 are arranged. If only the belt-like portion 20C is used, the shape of the weir member 20 is simplified, which is preferable.

  The dimensions of the weir member 20 and the surrounding portions in the above embodiment are merely specific examples, and the present invention is not limited to this. For example, since silver particles and foreign substances are considered to diffuse uniformly from the electrodes 10A and 10B and the gap c1 to the periphery thereof, the dam member can be arranged so that the distance between the electrode and the gap and the dam member is reduced. If so, the length of the belt-shaped portion may be reduced correspondingly. In addition, the height H1 of the weir member shown in the above embodiment is a preferable range when the distance H2 from the surface of the substrate 3 to the inner peripheral bottom surface of the case 1 is about 1.2 mm. Even if they float slightly from the surface of 3, they are high enough to dam up them. Therefore, the height H1 of the weir member may be appropriately set according to the distance H2. In the above embodiment, a gap is provided between the weir member 20 and the inner peripheral bottom surface of the case 1. However, the weir member may be in close contact with the inner peripheral bottom surface of the case without the gap.

  In the above embodiment, the electrodes 10A and 10B are provided in the vicinity of the connector 9, but the present invention can also be applied when the electrodes and the connector are provided apart in the longitudinal direction of the substrate. . In such a case, the dam member may be formed separately at positions corresponding to the electrodes and the connectors.

  The image reading apparatus A in the above embodiment is an example used by being assembled in a scanner that is fed by a platen roller, but is not limited to this. The image reading apparatus according to the present invention can be widely used by being assembled in various devices such as a so-called flatbed type scanner and a handy scanner that can read an image.

1 is an exploded perspective view illustrating an example of an image reading apparatus according to the present invention. It is sectional drawing which follows the II-II line | wire of FIG. It is sectional drawing which follows the III-III line | wire of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is the same figure as FIG. 4 which shows the other example of the image reading apparatus which concerns on this invention. It is a disassembled perspective view which shows an example of the conventional image reading apparatus. It is sectional drawing which follows the VII-VII line of FIG. It is a figure similar to FIG. 7 which shows the other example of the conventional image reading apparatus.

Explanation of symbols

A Image reading device 1 Case 1c Notch 3 Substrate 9 Connector 10A, 10B Electrode 20 Weir member 20A First strip 80 Light receiving element

Claims (5)

A case, a band plate-like substrate assembled to the case, and a plurality of image reading units provided on the substrate so as to be accommodated in the case and arranged in a line in the longitudinal direction of the substrate a light receiving element, respectively formed by applying a conductive paste to the casing and the base plate comprises an electrode at least part of them facing each other, and an image reading apparatus,
An image reading apparatus, wherein a weir member protruding in the thickness direction of the substrate is provided between the plurality of light receiving elements on the substrate and the electrode. The board is provided with a connector for connecting the board to an external device, and the case is provided with a notch for avoiding interference with the connector.
The image reading apparatus according to claim 1, wherein the dam member is provided between the plurality of light receiving elements and the notch.   3. The image reading apparatus according to claim 1, wherein the dam member has a belt-like portion extending in a direction substantially the same as a direction in which the plurality of light receiving elements are arranged.   The image reading device according to claim 1, wherein the dam member is made of a synthetic resin.   The image reading device according to claim 4, wherein the weir member is made of silicone resin.

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